AU616490B2 - Magnetic record medium and method of recording and reproducing security information on and from the same - Google Patents

Magnetic record medium and method of recording and reproducing security information on and from the same Download PDF

Info

Publication number
AU616490B2
AU616490B2 AU31646/89A AU3164689A AU616490B2 AU 616490 B2 AU616490 B2 AU 616490B2 AU 31646/89 A AU31646/89 A AU 31646/89A AU 3164689 A AU3164689 A AU 3164689A AU 616490 B2 AU616490 B2 AU 616490B2
Authority
AU
Australia
Prior art keywords
changes
security information
record medium
information
magnetic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
AU31646/89A
Other languages
English (en)
Other versions
AU3164689A (en
Inventor
Minoru Fujita
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kyodo Printing Co Ltd
Original Assignee
Kyodo Printing Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kyodo Printing Co Ltd filed Critical Kyodo Printing Co Ltd
Publication of AU3164689A publication Critical patent/AU3164689A/en
Application granted granted Critical
Publication of AU616490B2 publication Critical patent/AU616490B2/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/02—Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
    • G11B5/09—Digital recording
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07F—COIN-FREED OR LIKE APPARATUS
    • G07F7/00—Mechanisms actuated by objects other than coins to free or to actuate vending, hiring, coin or paper currency dispensing or refunding apparatus
    • G07F7/08—Mechanisms actuated by objects other than coins to free or to actuate vending, hiring, coin or paper currency dispensing or refunding apparatus by coded identity card or credit card or other personal identification means
    • G07F7/086—Mechanisms actuated by objects other than coins to free or to actuate vending, hiring, coin or paper currency dispensing or refunding apparatus by coded identity card or credit card or other personal identification means by passive credit-cards adapted therefor, e.g. constructive particularities to avoid counterfeiting, e.g. by inclusion of a physical or chemical security-layer
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/08—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes
    • G06K7/082—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes using inductive or magnetic sensors
    • G06K7/083—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes using inductive or magnetic sensors inductive
    • G06K7/084—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes using inductive or magnetic sensors inductive sensing magnetic material by relative movement detecting flux changes without altering its magnetised state
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/14—Digital recording or reproducing using self-clocking codes
    • G11B20/1403—Digital recording or reproducing using self-clocking codes characterised by the use of two levels
    • G11B20/1407—Digital recording or reproducing using self-clocking codes characterised by the use of two levels code representation depending on a single bit, i.e. where a one is always represented by a first code symbol while a zero is always represented by a second code symbol
    • G11B20/1419—Digital recording or reproducing using self-clocking codes characterised by the use of two levels code representation depending on a single bit, i.e. where a one is always represented by a first code symbol while a zero is always represented by a second code symbol to or from biphase level coding, i.e. to or from codes where a one is coded as a transition from a high to a low level during the middle of a bit cell and a zero is encoded as a transition from a low to a high level during the middle of a bit cell or vice versa, e.g. split phase code, Manchester code conversion to or from biphase space or mark coding, i.e. to or from codes where there is a transition at the beginning of every bit cell and a one has no second transition and a zero has a second transition one half of a bit period later or vice versa, e.g. double frequency code, FM code
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/14—Digital recording or reproducing using self-clocking codes
    • G11B20/1403—Digital recording or reproducing using self-clocking codes characterised by the use of two levels
    • G11B20/1423—Code representation depending on subsequent bits, e.g. delay modulation, double density code, Miller code

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Security & Cryptography (AREA)
  • Artificial Intelligence (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Theoretical Computer Science (AREA)
  • Signal Processing For Digital Recording And Reproducing (AREA)
  • Digital Magnetic Recording (AREA)
  • Recording Or Reproducing By Magnetic Means (AREA)
AU31646/89A 1988-03-30 1989-03-23 Magnetic record medium and method of recording and reproducing security information on and from the same Ceased AU616490B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP63074675A JPH01248301A (ja) 1988-03-30 1988-03-30 磁気記録媒体およびそのセキュリティ情報の記録再生方法
JP63-74675 1988-03-30

Publications (2)

Publication Number Publication Date
AU3164689A AU3164689A (en) 1989-10-05
AU616490B2 true AU616490B2 (en) 1991-10-31

Family

ID=13554041

Family Applications (1)

Application Number Title Priority Date Filing Date
AU31646/89A Ceased AU616490B2 (en) 1988-03-30 1989-03-23 Magnetic record medium and method of recording and reproducing security information on and from the same

Country Status (6)

Country Link
JP (1) JPH01248301A (ko)
KR (1) KR930001701B1 (ko)
AU (1) AU616490B2 (ko)
GB (1) GB2217096B (ko)
HK (1) HK106993A (ko)
SG (1) SG27393G (ko)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2367182B (en) 2000-09-20 2004-05-26 Hewlett Packard Co Improvements in and relating to data protection

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4219851A (en) * 1978-11-24 1980-08-26 Honeywell Information Systems Inc. Group coded recording data recovery system
US4342054A (en) * 1979-06-06 1982-07-27 Nakamichi Corporation Information read device

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5942617A (ja) * 1982-08-31 1984-03-09 Sansui Electric Co 磁気記録再生方式
JPS5960713A (ja) * 1982-09-30 1984-04-06 Sansui Electric Co 磁気記録再生方式

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4219851A (en) * 1978-11-24 1980-08-26 Honeywell Information Systems Inc. Group coded recording data recovery system
US4342054A (en) * 1979-06-06 1982-07-27 Nakamichi Corporation Information read device

Also Published As

Publication number Publication date
SG27393G (en) 1993-05-21
AU3164689A (en) 1989-10-05
HK106993A (en) 1993-10-22
JPH01248301A (ja) 1989-10-03
GB2217096B (en) 1992-01-22
GB2217096A (en) 1989-10-18
GB8906646D0 (en) 1989-05-04
KR930001701B1 (ko) 1993-03-11
KR890015243A (ko) 1989-10-28

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Legal Events

Date Code Title Description
MK14 Patent ceased section 143(a) (annual fees not paid) or expired